Swarm of Bloodflies

A red shimmering swarm of bloodflies pursues their target within range and burrows into their skin drinking their blood, causing the target to make a constitution save. On a failed save, the target takes 2d12 necrotic damage immediately and 1d12 necrotic damage at the end of its next turn. On a successful save, the target takes half damage (both initial and later).

Constructs, Plants, and undead are not affected by this damage.

At Higher Levels. When you cast this spell using a spell slot of 3rd level or higher, the damage (both initial and later) increases by 1d12 for each slot level above 2nd.